1. Field of the Invention
Generally, the invention relates to systems for production of a realistic graphical view of an environment to be encountered during movement of a vehicle. More specifically, the invention relates to such systems for use with rail vehicles to provide the operator of locomotives with useful information about conditions to be encountered including information about upcoming track and highway crossings.
2. Description of the Prior Art
Rail based vehicles travel along fixed position rail tracks. Typically, such rail tracks have numerous junctures where a selection of divergent rail paths may be taken. Typically, rail based vehicles travel along a respective path during a specific trip with various predetermined path options being implemented. Numerous segments of rail tracks exist throughout the world, with many of these segments located in the United States of America. Most, if not all, of such rail tracks have been precisely surveyed with detailed identifying data encoded in computational databases. Applicable identifying data including information sufficient to determine precise coordinates of location and elevation along a path of a respective section of the rail track. Such identifying data may include precise path descriptions, track branching descriptions, track intersection point descriptions with other tracks, land based roads and highways, bridge descriptions and tunnel descriptions.
Positive train control (PTC) systems are integrated command, control, communications, and information systems conventionally known in the art for controlling train movements with safety, security, precision, and efficiency. Positive train control systems improve railroad safety by significantly reducing the probability of collisions between trains, casualties to roadway workers and damage to their equipment, and over speed accidents.
Positive train control systems may have digital data link communications networks, continuous and accurate positioning systems, on-board computers with digitized maps on locomotives and maintenance-of-way equipment, in-cab displays, throttle-brake interfaces on locomotives, wayside interface units at switches and wayside detectors, and control center computers and displays.
Various methods are known in the art to determine a location of an object, including a moving object. GPS (global positioning system) devices are well known in the art to determine a position measurement.
Radio frequency identification (RFID) tags are known to store information which may be retrieved by a receiver. RFID tags may be positioned in fixed locations with the stored information indicative of the location of the respective RFID tag. Radio frequency identification (RFID) is an identification method, relying on storing and remotely retrieving data using devices called radio frequency identification tags or transponders. A radio frequency identification tag can be positioned relative to a location, attached to an object or inserted into an object, animal or person. Once deployed the radio frequency identification tag may be identified using radio waves. Chip-based radio frequency identification tags contain silicon chips and antennas. Passive radio frequency identification tags require no internal power source, whereas active radio frequency identification tags require a power source.
Passive radio frequency identification tags have no internal power supply. The minute electrical current induced in the antenna by an incoming radio frequency signal provides just enough power for the complementary-symmetry/metal-oxide semiconductor (CMOS) integrated circuit in the tag to power up and transmit a response. Most passive tags signal by backscattering the carrier signal from the reader. This means that the aerial, or antenna, has to be designed to both collect power from the incoming signal and also to transmit the outbound backscatter signal. The response of a passive radio frequency identification tag does not have to be just a simple identification number but can contain nonvolatile storing data.
Active radio frequency identification tags have their own internal power source. Active radio frequency signal tags are typically much more reliable than passive tags due to the ability of active tags to conduct a “session” with a reader. Active radio frequency signal tags, due to their onboard power supply, also transmit at higher power levels than passive radio frequency signal tags, allowing them to be more effective in radio frequency challenged environments like water, metal, or at longer distances. Many active radio frequency signal tags have practical ranges of hundreds of feet with a battery life of up to 10 years. Active tags typically have much larger memories than passive radio frequency signal tags. Additionally, active radio frequency signal may have the ability to store information sent by the transceiver.
Numerous methods exist to improve rail based vehicle safety. Various systems and methods have been proposed to inform the operator of a location of the train along the track including orientation to rail track and highway crossings and speed of the train. Various systems and methods have been proposed to increase safety at rail track and highway crossings. Many of these systems and methods involve notifying, or otherwise alerting, the operators of highway vehicles and pedestrians of the approach of the train.
Traditionally, the operator of a rail based vehicle activates the audible horn sound approximately one-quarter mile from a rail track and highway crossing. The horn warns motorists and pedestrians approaching the intersection that the rail based vehicle is approaching. To be heard over this distance, the audible horn sound must be very loud. This combination of loud horns and the length along the tracks that the horn is sounded creates a large area adversely impacted by the horn noise. In urban areas, this area likely includes many nearby residential dwellings.
An innovation in rail track and highway crossing warning involves providing a similar audible warning to motorists and pedestrians by using two stationary horns mounted at the crossing. Each horn directs its sound toward the approaching roadway. The land based horn system typically is activated using the same track-signal circuitry as the gate arms and bells located at the crossing. Once the land based horns are activated, a strobe light begins flashing to inform the rail based vehicle operator that the horns has been activated and are working. Horn volume data collected near the crossings clearly demonstrate the significant reduction of land area negatively impacted by using the land based horn system. Residents overwhelmingly accepted the land based horn systems and noted a significant improvement in their quality of life. Motorists also prefer the land based horn systems. The rail based vehicle operators rated these crossings slightly safer compared to the same crossings before the change to the land based horn system.
Various automated crossing guards deployment, with audio and visual alerting, having been proposed. Many crossings, particularly in rural areas, lack crossing arms which are lowered to block traffic while trains pass. Various train mounted horn soundings are mandated when approaching crossings to warn highway vehicle operators of the approach of the train. Typically such train mounted horn soundings are manually activated by the operator of the train although automated activation systems are known in the art. Due to the extremely long stopping distance of typical trains, depending upon various factors including speed of the train and weight of the train, it typically falls to the highway vehicle operators to remain out of the path of the train. Therefore it is of paramount importance to provide proper audio warning of the approach of trains. This is complicated due to a strong desire of train operators not to unduly disturb persons residing near rail track and highway crossings with premature activation of horn sounding when approaching the crossing. Further complicating such horn soundings is that trains travel at various speeds, depending upon many factors, when passing respective crossings. Additionally, trains operate around the clock including at night when visibility is limited to the operator of the train. Trains also operate in all weather conditions including during heavy rain, during snow storms, including white out conditions, and during periods when dense fog is present. These conditions often cause the operator to come upon a crossing without the desired time interval to properly activate the horn soundings. Various systems and methods have been proposed to notify the operator of the train to manually activate the horn soundings or to automatically activate the horn soundings. In the field of automated activation of the horn soundings when approaching crossings, conventionally known systems typically rely upon a fixed point along the track which when arrived at activates the horn soundings. These systems typically do not afford the capacity to factor in other relevant information such as the speed of the train, the weight or length of the train, and conditions affecting visibility, such as the time of day or night.
As can be seen various attempts have been made to improve safety of the operation of trains including such operation at track and highway crossings. These attempts have been less efficient than desired. As such, it may be appreciated that there continues to be a need for a system which provides relevant data to the operator of the train in a visual format which the operator can readily understand and utilize in any operating condition including at night and during periods of adverse weather conditions. The present invention substantially fulfills these needs.